The present invention relates, in general, to nibbling tools and more particularly to a nibbler apparatus providing a means for cutting sheet metal or the like by the use of a rotating cutter with a modified sinusoidal groove of a pre-determined width and depth.
Nibbler tools, which are sheet metal cutters, have a number of problems associated with them. One of the dangers, even to skilled personnel, of sheet metal cutters, is the exposure of the cutting surfaces. In the prior art the sheet metal is cut during the down cycle of the up and down movement which exposes the cutting surfaces, thereby exposing the user to unnecessary hazards.
Further, the reciprocating motion creating movement for the cutter, has been provided, in certain nibbler tools, by the operation of a cam. The tensile and bending stresses normally encountered by nibbler tools causes premature wear and possible destruction.
Another problem associated with nibbler tools has been caused by the use of a straight helical cutting thread design, which may increase the force and impact of the cutter against the metal and thereby produce ragged cut edges.
Accordingly, an object of the present invention is to provide new and unique nibbler tools.
Another related object of the present invention is to provide nibbler tools comprising a few parts with quickly changeable rotating cutters having modified sinusoidal grooves of a predetermined width and depth.
Further, it is an object of this invention to provide rotating cutters which are mounted in a die without exposing the cutting curfaces.
Another object of the invention is to provide rotating cutters with a modified sinusoidal groove for producing smooth cut edges. Further, the rotating cutters are protected from being inadvertently damaged because they are protected by the die at all times. In addition, the location of the cutters in the dies provides safety to the user because the rotating cutter is not exposed beyound the die opening.
These and other objects of the invention will become apparent as described in the present disclosure.